What is the Difference Between Chemistry and Physics?
On a fundamental level, chemistry can be explained by physics. The atoms that make up the periodic table elements are themselves made of quantum particles.
Given this truth, although it isn’t practical, one could theoretically explain all chemical compounds and reactions in terms of quantum physics.
At a core level, the main difference between physics and chemistry is how “quanta” (the quantum particles of the standard model of quantum physics) have organized themselves in naturally occurring relationships arising from nucleosynthesis (stars exploding). When enough composite particles bind together in geometric patterns creating molecules, we stop considering physics and start dealing with the rule-sets of chemistry.
Everything from the quarks and electrons that make up the elements, to cell-based organisms, can be explained by fundamental particle interactions. There are no physical phenomena that happen on the chemical level, either in systems or between systems, that is not explained by quantum physics.
Introduction to Chemistry. Chemistry is physics starting at the point when quanta organize into atoms and elements.
TIP: This argument is contingent. All we are saying is that the basis of the universe is quantum particles (quanta), so thus all real physical systems (including everything related to chemistry) is at its core physics.
TIP: One can explain both physics and chemistry using mathematics, but this argument is more about the mathematics-based rules for the universe than about what everything is made out of.
Physics Can Be Explained By Little More Than the Standard Model
On some level, everything that isn’t “nothing” can be explained by quantum physics. Namely, the four forces and elementary particles. There are some unknowns in the universe, like dark energy, but that aside, the building blocks of the universe are “quanta.”
Quantum physics can largely be explained by QFT (Quantum Field Theory), and largely just by QED (Quantum Electro Dynamics, the study of electromagnetic energy (one of the four forces) on the quantum level, of which a small frequency is visible light).
So on an even more fundamental level, most of physics and chemistry can be explained in terms of “light.”
There isn’t much more to it than this on the most basic level. From these simple truths come the endless complexity of the universe of which the chemical bonding of composite particles into the periodic table elements accounts for only a small part. Matter is a little less than 5% of the total universe, and much of it is a simple gas like hydrogen.
Please look at our section on chemistry and Crash Course Chemistry on YouTube as well as our section of physics and Crash Course Physics on YouTube. It is worth hearing about it from Richard Feynman.
QED: Photons — Corpuscles of Light — Richard Feynman (1/4). You know, back before internet you couldn’t just sit down with Richard Feynmen and get a lecture on QED without enrolling in theoretical physics course at Caltech. But today, with all this fancy mastery of mass-energy and physics, we have YouTube. NOTE: Feynman as in the Feynman diagrams that model quantum theory.
What is an atom? It is composite particles (nucleus, protons, neutrons) made from quanta (electrons, photons, quarks). What is an element? It is atoms arranged in geometric patterns based on quantum interactions (a substance consisting of atoms which all have the same atomic number). What is an organism? It is a cell-based life form made of elements, made from atoms, made from quanta. So what is chemistry at its core? Physics ruled by mathematics.
FACT: On another level, everything is “massless energy particles” i.e. mass-energy in motion or what one would call in laymen’s terms “light” or more properly “electromagnetic energy.”
FACT: Strange right? It is this line of thinking that gets people thinking about far-out theories like the simulation argument.
A Quote The [Richard] Feynman Lectures on Physics (1964)
“A poet once said, “The whole universe is in a glass of wine.” We will probably never know in what sense he meant that for poets do not write to be understood. But it is true that if we look at a glass of wine closely enough, we see the entire universe. There are the things of physics: the twisting liquid which evaporates depending on the wind and weather, the reflections in the glass, and our imagination adds the atoms. The glass is a distillation of the Earth’s rocks, and in its composition we see the secrets of the universe’s age, and the evolution of stars. What strange arrays of chemicals are in the wine? How did they come to be? There are the ferments, the enzymes, the substrates, and the products. There in wine is found the great generalization: all life is fermentation. Nobody can discover the chemistry of wine without discovering, as did Louis Pasteur, the cause of much disease. How vivid is the claret, pressing its existence into the consciousness that watches it! If our small minds, for some convenience, divide this glass of wine, this universe, into parts — physics, biology, geology, astronomy, psychology, and so on — remember that nature does not know it! So let us put it all back together, not forgetting ultimately what it is for. Let it give us one more final pleasure: drink it and forget it all!” – volume I; lecture 3, “The Relation of Physics to Other Sciences”; section 3-7, “How did it get that way?”; p. 3-10